USP18 and systemic lupus erythematosus: Moreover, disease marker analysis of these 26 genes clearly showed that a series of more important genes (14/26) are directly related to SLE, including CD180, MDM2, KLHDC7B, USP18, TLR8, DDX60, CD163, PXK, JAK2, GSTP1, CISH, GPX1, RGL1, and CCR1 (Figure 5C).